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金仓数据库KingbaseES客户端编程接口指南-DCI（5. 程序示例）
5. 程序示例
5.1. 登录和注销数据库
#include "dci.h" /* DCI接口头文件 */ #include
#include #include DCIEnv *envhp; /* 环境句柄 */ DCIError *errhp; /* 错误句柄 */ DCISvcCtx *svchp; /* 上下文句柄 */ DCIStmt *stmthp = (DCIStmt *)NULL; /* 语句句柄 */ /* 初始化各种句柄 */ sword init_handles(DCIEnv **envhp, DCIError **errhp) { printf("Environment setup ....\n"); /* 初始化DCI应用环境 */ if (DCIInitialize(DCI_DEFAULT, (dvoid *)0, (dvoid * (*)(dvoid *, size_t))0, (dvoid * (*)(dvoid *, dvoid *, size_t))0, (void (*)(dvoid *, dvoid *))0)) { printf("FAILED: DCIInitialize()\n"); return DCI_ERROR; } /* 初始化环境句柄 */ if (DCIEnvInit((DCIEnv **)envhp, (ub4)DCI_DEFAULT, (size_t)0, (dvoid **)0)) { printf("FAILED: DCIEnvInit()\n"); return DCI_ERROR; } /* 从环境句柄上分配一个错误信息句柄 */ if (DCIHandleAlloc((dvoid *)*envhp, (dvoid **)errhp, (ub4)DCI_HTYPE_ERROR, (size_t)0, (dvoid **)0)) { printf("FAILED: DCIHandleAlloc() on errhp\n"); return DCI_ERROR; } return DCI_SUCCESS; } /* 使用给定的用户名和口令登录到指定的数据库服务上 */ sword log_on(DCIEnv *envhp, DCIError *errhp, text *uid, text *pwd, text *DbName) { printf("Logging on as %s ....\n", uid); /* 连接数据库，在 DCILogon 中分配 Service handle */ if (DCILogon(envhp, errhp, &svchp, uid, (ub4)strlen((char *)uid),pwd, (ub4)strlen((char *)pwd), DbName, (ub4)strlen((char *)DbName))) { printf("FAILED: DCILogon()\n"); return DCI_ERROR; } printf("%s logged on.\n", uid); return DCI_SUCCESS; } /* 断开连接，并释放各种句柄 */ sword finish_demo(boolean loggedon, DCIEnv *envhp, DCISvcCtx *svchp, DCIError *errhp, DCIStmt *stmthp) { if (stmthp) DCIHandleFree((dvoid *)stmthp, (ub4)DCI_HTYPE_STMT); printf("logoff ...\n"); if (loggedon) DCILogoff(svchp, errhp); printf("Freeing handles ...\n"); if (svchp) DCIHandleFree((dvoid *)svchp, (ub4)DCI_HTYPE_SVCCTX); if (errhp) DCIHandleFree((dvoid *)errhp, (ub4)DCI_HTYPE_ERROR); if (envhp) DCIHandleFree((dvoid *)envhp, (ub4)DCI_HTYPE_ENV); return DCI_SUCCESS; } /* 打印错误信息 */ void report_error(DCIError *errhp) { text msgbuf[512]; sb4 errcode = 0; DCIErrorGet((dvoid *)errhp, (ub4)1, (text *)NULL, &errcode, msgbuf, (ub4)sizeof(msgbuf), (ub4)DCI_HTYPE_ERROR); printf("ERROR CODE = %d", errcode); printf("%.*s\n", 512, msgbuf); return; } /* 主程序入口 */ int main() { text *DbName = (text *)"KingbaseES"; /* 配置文件 sys_service.conf 中配置的数据源名 */ text *username = (text *)"SYSTEM"; /* 用户名 */ text *password = (text *)"MANAGER"; /* 密码 */ int logged_on = FALSE; /* 初始化各种句柄 */ if (init_handles(&envhp, &errhp) != DCI_SUCCESS) { printf("FAILED: init_handles()\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 登录到数据库服务 */ if (log_on(envhp, errhp, username, password, DbName) != DCI_SUCCESS) { printf("FAILED: log_on()\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 在这里执行SQL语句 */ logged_on = TRUE; /* 断开连接，清理各种句柄 */ return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } 5.2. 执行一条不返回结果的 SQL 语句
为了节省篇幅，本示例不再重复写出上面示例中实现的 init_handles、log_on、finish_demo 和 report_error 等函数，以及包含的头文件列表，仅给出主函数的实现。
int main() { text *DbName = (text *)"KingbaseES"; /* 配置文件 sys_service.conf 中配置的数据源名 */ text *username = (text *)"SYSTEM"; /* 用户名 */ text *password = (text *)"MANAGER"; /* 口令 */ int logged_on = FALSE; char sql[1024]; /* 初始化各种句柄 */ if (init_handles(&envhp, &errhp)) { printf("FAILED: init_handles()\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 登录到数据库服务 */ if (log_on(envhp, errhp, username, password, DbName)) { printf("FAILED: log_on()\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } logged_on = TRUE; if (DCIHandleAlloc((dvoid *)envhp, (dvoid **)&stmthp, (ub4)DCI_HTYPE_STMT, (CONST size_t)0, (dvoid **)0)) { printf("FAILED: alloc statement handle\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 准备一条建表语句 */ strcpy(sql, "CREATE TABLE T(C INT)"); if (DCIStmtPrepare(stmthp, errhp, (unsigned char *)sql, (ub4)strlen((char *)sql), (ub4)DCI_NTV_SYNTAX, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtPrepare() select\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 非查询类型语句，iters参数必需>=1 */ if (DCIStmtExecute(svchp, stmthp, errhp, (ub4)1, (ub4)0, (CONST DCISnapshot *)0, (DCISnapshot *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtExecute() select\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 登出数据库服务，并清理各种句柄 */ return finish_demo(logged_on, envhp, svchp, errhp, stmthp); }5.3. 执行一条查询语句并获取结果
为了节省篇幅，本示例不再重复写出上面示例中实现的 init_handles、log_on、finish_demo 和 report_error 等函数，以及包含的头文件列表，仅给出主函数的实现。
/* 以列绑定的形式来获取数据，每一列的值都连续的存放在一起。 * rows参数表示每次获取的数据行数 * 假定表T的结构为 * T(C1 INT, C2 REAL, C3 CHAR(100 BYTE), C4 VARCHAR(100 BYTE), * C5 FLOAT, C6 NUMERIC(22,7), C7 TIME) */ #define CHAR_SIZE 101 sword Select_ColumnBind(ub2 rows) { text *sqlstmt = (text *)"select C1, C2, C3, C4, C5, C6, C7 from T"; int *c1 = (int *)malloc(sizeof(int) * rows); float *c2 = (float *)malloc(sizeof(float) * rows); DCIDate *c7 = (DCIDate *)malloc(sizeof(DCIDate) * rows); char *c3 = (char *)malloc(sizeof(char) * rows * CHAR_SIZE); char *c4 = (char *)malloc(sizeof(char) * rows * CHAR_SIZE); float *c5 = (float *)malloc(sizeof(float) * rows); DCINumber *c6 = (DCINumber *)malloc(sizeof(DCINumber) * rows); DCIDefine *bndhp[7]; ub4 stmrow, stmrowEx; /* 准备查询语句 */ if (DCIStmtPrepare(stmthp, errhp, sqlstmt, (ub4)strlen((char *)sqlstmt), (ub4)DCI_NTV_SYNTAX, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtPrepare() select\n"); report_error(errhp); return DCI_ERROR; } memset(c1, 0, sizeof(int) * rows); memset(c2, 0, sizeof(int) * rows); memset(c3, 0, rows * CHAR_SIZE); memset(c4, 0, rows * CHAR_SIZE); memset(c5, 0, sizeof(float) * rows); memset(c6, 0, sizeof(DCINumber) * rows); memset(c7, 0, sizeof(DCIDate) * rows); /* 绑定缓冲区到相对应的列上 */ if (DCIDefineByPos(stmthp, &bndhp[0], errhp, 1, (dvoid *)c1, (sb4)sizeof(int), (ub2)SQLT_INT, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &bndhp[1], errhp, 2, (dvoid *)c2, (sb4)sizeof(float), (ub2)SQLT_FLT, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &bndhp[2], errhp, 3, (dvoid *)c3, (sb4)CHAR_SIZE, (ub2)SQLT_CHR, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &bndhp[3], errhp, 4, (dvoid *)c4, (sb4)CHAR_SIZE, (ub2)SQLT_STR, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &bndhp[4], errhp, 5, (dvoid *)c5, (sb4)sizeof(float), (ub2)SQLT_FLT, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &bndhp[5], errhp, 6, (dvoid *)c6, (sb4)sizeof(DCINumber), (ub2)SQLT_VNU, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &bndhp[6], errhp, 7, (dvoid *)c7, (sb4)sizeof(DCIDate), (ub2)SQLT_ODT, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } /* 指定每一列的每个值的间隔长度 */ if (DCIDefineArrayOfStruct(bndhp[0], errhp, sizeof(int), 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineArrayOfStruct(bndhp[1], errhp, sizeof(float), 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineArrayOfStruct(bndhp[2], errhp, CHAR_SIZE, 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineArrayOfStruct(bndhp[3], errhp, CHAR_SIZE, 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineArrayOfStruct(bndhp[4], errhp, sizeof(float), 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineArrayOfStruct(bndhp[5], errhp, sizeof(DCINumber), 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineArrayOfStruct(bndhp[6], errhp, sizeof(DCIDate), 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } /* 执行查询语句 */ if (DCIStmtExecute(svchp, stmthp, errhp, (ub4)0, (ub4)0, (CONST DCISnapshot *)0, (DCISnapshot *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtExecute() select\n"); report_error(errhp); return DCI_ERROR; } stmrowEx = 0; while (1) { if (DCIStmtFetch(stmthp, errhp, rows, DCI_FETCH_NEXT, 0) == DCI_ERROR) break; /* 获取多次提取总共返的记录的行数 */ DCIAttrGet(stmthp, DCI_HTYPE_STMT, &stmrow, 0, DCI_ATTR_ROW_COUNT, errhp); if (stmrow == stmrowEx) /* 没有新行被获取，那么跳出 */ break; printf("提取到了%d行记录\n", stmrow - stmrowEx); /* 你可以在这里处理获取到的数据 */ for (int i = 0; i < rows; i++) { printf("*************第%d行****************\n", i + 1); printf("c1: %d,\t c2:%f\n", c1[i], c2[i]); printf("c3: %s\n", c3 + CHAR_SIZE * i); printf("c4: %s\n", c4 + CHAR_SIZE * i); char c6fmt[] = "999999999999999999999.9999999"; /* 22个9.7个9 */ char c6str[255]; int outlen; DCINumberToText(errhp, &c6[i], (DciText *)c6fmt, (ub4)strlen(c6fmt), NULL, 0, (ub4 *)&outlen, (DciText *)c6str); c6str[outlen] = 0; printf("c5: %f,\t c6:%s\n", c5[i], c6str); printf("c7: %d-%d-%d %d:%d:%d\n", (int)c7[i].DCIDateYYYY, c7[i].DCIDateMM, c7[i].DCIDateDD, c7[i].DCIDateTime.DCITimeHH, c7[i].DCIDateTime.DCITimeMI, c7[i].DCIDateTime.DCITimeSS); } stmrowEx = stmrow; } if (DCITransCommit(svchp, errhp, (ub4)DCI_DEFAULT)) { printf("FAILED: DCITransCommit() select\n"); report_error(errhp); return DCI_ERROR; } free(c1); free(c2); free(c3); free(c4); free(c5); free(c6); free(c7); return DCI_SUCCESS; } /* 采用整行绑定的方式来获取记录，值的存放类似自然表格的形式 * rows参数表示每次获取的数据行数 * 假定表T的结构为 * T(C1 INT, C2 REAL, C3 CHAR(100 BYTE), C4 VARCHAR(100 BYTE), * C5 FLOAT, C6 NUMERIC(22,7), C7 DATETIME) */ sword Select_RowBind(ub2 rows) { text *sqlstmt = (text *)"select C1, C2, C3, C4, C5, C6, C7 from T"; char *p; DCIDefine *bndhp[7]; int *c1; float *c2; char *c3; char *c4; float *c5; DCINumber *c6; DCIDate *c7; ub4 stmrow, stmrowEx; /* 计算出一行记录的总大小，以便用来设置每列值存贮的间隔大小 */ int row_size = sizeof(int) + sizeof(float) + sizeof(DCIDate) + CHAR_SIZE + CHAR_SIZE + sizeof(DCINumber) + sizeof(float); p = (char *)malloc(sizeof(char) * row_size * rows); memset(p, 0, row_size * rows); if (DCIStmtPrepare(stmthp, errhp, sqlstmt, (ub4)strlen((char *)sqlstmt), (ub4)DCI_NTV_SYNTAX, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtPrepare() select\n"); report_error(errhp); return DCI_ERROR; } c1 = (int *)p; c2 = (float *)((char *)c1 + sizeof(int)); c3 = ((char *)c2 + sizeof(float)); c4 = (char *)c3 + CHAR_SIZE; c5 = (float *)((char *)c4 + CHAR_SIZE); c6 = (DCINumber *)((char *)c5 + sizeof(float)); c7 = (DCIDate *)((char *)c6 + sizeof(DCINumber)); if (DCIDefineByPos(stmthp, &bndhp[0], errhp, 1, (dvoid *)c1, (sb4)4, (ub2)SQLT_INT, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &bndhp[1], errhp, 2, (dvoid *)c2, (sb4)4, (ub2)SQLT_FLT, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &bndhp[2], errhp, 3, (dvoid *)c3, (sb4)CHAR_SIZE, (ub2)SQLT_CHR, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &bndhp[3], errhp, 4, (dvoid *)c4, (sb4)CHAR_SIZE, (ub2)SQLT_STR, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &bndhp[4], errhp, 5, (dvoid *)c5, (sb4)4, (ub2)SQLT_FLT, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &bndhp[5], errhp, 6, (dvoid *)c6, (sb4)4, (ub2)SQLT_VNU, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &bndhp[6], errhp, 7, (dvoid *)c7, (sb4)sizeof(DCIDate), (ub2)SQLT_ODT, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } /* 设置每列的值存放间隔大小，它的大小为一行记录的大小 */ if (DCIDefineArrayOfStruct(bndhp[0], errhp, row_size, 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineArrayOfStruct(bndhp[1], errhp, row_size, 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineArrayOfStruct(bndhp[2], errhp, row_size, 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineArrayOfStruct(bndhp[3], errhp, row_size, 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineArrayOfStruct(bndhp[4], errhp, row_size, 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineArrayOfStruct(bndhp[5], errhp, row_size, 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineArrayOfStruct(bndhp[6], errhp, row_size, 0, 0, 0)) { printf("FAILED: DCIDefineArrayOfStruct()\n"); report_error(errhp); return DCI_ERROR; } if (DCIStmtExecute(svchp, stmthp, errhp, (ub4)0, (ub4)0, (CONST DCISnapshot *)0, (DCISnapshot *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtExecute() select\n"); report_error(errhp); return DCI_ERROR; } stmrowEx = 0; while (1) { if (DCIStmtFetch(stmthp, errhp, rows, DCI_FETCH_NEXT, 0) == DCI_ERROR) break; /* 获取多次提取总共返的记录的行数 */ DCIAttrGet(stmthp, DCI_HTYPE_STMT, &stmrow, 0, DCI_ATTR_ROW_COUNT, errhp); if (stmrow == stmrowEx) /* 没有新行被获取，那么跳出 */ break; printf("提取到了%d行记录\n", stmrow - stmrowEx); /* 你可以在这里处理获取到的数据 */ for (int i = 0; i < rows; i++) { int *c1tmp = (int *)((char *)c1 + i * row_size); float *c2tmp = (float *)((char *)c2 + i * row_size); char *c3tmp = c3 + i * row_size, *c4tmp = c4 + i * row_size; float *c5tmp = (float *)((char *)c5 + i * row_size); DCINumber *c6tmp = (DCINumber *)((char *)c6 + i * row_size); DCIDate *c7tmp = (DCIDate *)((char *)c7 + i * row_size); printf("*************第%d行****************\n", i + 1); printf("c1: %d,\t c2:%f\n", *c1tmp, *c2tmp); printf("c3: %s\n", c3tmp); printf("c4: %s\n", c4tmp); char c6fmt[] = "999999999999999999999.9999999"; /* 22个9.7个9 */ char c6str[255]; int outlen; DCINumberToText(errhp, c6tmp, (DciText *)c6fmt, (ub4)strlen(c6fmt), NULL, 0, (ub4 *)&outlen, (DciText *)c6str); c6str[outlen] = 0; printf("c5: %f,\t c6:%s\n", *c5tmp, c6str); printf("c7: %d-%d-%d %d:%d:%d\n", c7tmp->DCIDateYYYY, c7tmp->DCIDateMM, c7tmp->DCIDateDD,c7tmp->DCIDateTime.DCITimeHH, c7tmp->DCIDateTime.DCITimeMI,c7tmp->DCIDateTime.DCITimeSS); } stmrowEx = stmrow; } if (DCITransCommit(svchp, errhp, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtExecute() select\n"); report_error(errhp); return DCI_ERROR; } free(p); return DCI_SUCCESS; } /* 主程序入口 */ int main() { text *DbName = (text *)"KingbaseES"; text *username = (text *)"SYSTEM"; text *password = (text *)"MANAGER"; int logged_on = FALSE; /* 初始化各种句柄 */ if (init_handles(&envhp, &errhp)) { printf("FAILED: init_handles()\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 登录到数据库服务 */ if (log_on(envhp, errhp, username, password, DbName)) { printf("FAILED: log_on()\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } logged_on = TRUE; if (DCIHandleAlloc((dvoid *)envhp, (dvoid **)&stmthp, (ub4)DCI_HTYPE_STMT, (CONST size_t)0, (dvoid **)0)) { printf("FAILED: alloc statement handle\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 分别按照列和行的方式获取100行数据 */ Select_ColumnBind(100); Select_RowBind(100); /* 登出数据库服务，并清理各种句柄 */ return finish_demo(logged_on, envhp, svchp, errhp, stmthp); }5.4. 读取大字段数据
为了节省篇幅，本示例不再重复写出上面示例中实现的 init_handles、log_on、finish_demo 和 report_error 等函数，以及包含的头文件列表，仅给出主函数的实现。
#define COMMENT(x) (void)fprintf(stdout, "\nCOMMENT: %s\n", x) /* 读取一个大字段 */ void Read_from_loc(DCISvcCtx *svchp, DCIError *errhp, DCILobLocator *lobp) { ub1 *buf; ub4 readsize = 0; ub4 amtp; ub4 lenp = 0; sb4 err; COMMENT("Read from the locator."); /* 获取大字段的总长度 */ if (DCILobGetLength(svchp, errhp, lobp, &lenp) != DCI_SUCCESS) { COMMENT("Read_from_loc: DCILobGetLength"); return; } else { printf(" Length of Locator is %d\n", lenp); /* 如果是 CLOB ，那么需要多申请一个字节用来存放空结尾 */ buf = (ub1 *)malloc(sizeof(ub1) * (lenp + 1)); buf[lenp] = '\0'; } printf("\n--------------------------------------------------------------\n"); /* 读定位器 */ do { amtp = 1024; err = DCILobRead(svchp, errhp, lobp, &amtp, 1, buf + readsize, lenp + 1 - readsize, (dvoid *)0, (sb4(*)(dvoid *, const dvoid *, ub4, ub1))0, (ub2)0, (ub1)SQLCS_IMPLICIT); if (err == DCI_SUCCESS || err == DCI_NEED_DATA) readsize += amtp; /* 累加每次得到的数据长度 */ else COMMENT("Read_from_loc : DCILobRead"); } while (err == DCI_NEED_DATA); /* 已经读完，你可以在这里处理得到的数据，它的总长度存放在readsize里面 */ free(buf); } /* 分配一个大字段存贮描述结构指针 */ sword alloc_lob_desc(DCIEnv *envhp, DCILobLocator **lobsrc) { if (DCIDescriptorAlloc(envhp, (dvoid **)lobsrc, (ub4)DCI_DTYPE_LOB, (size_t)0, (dvoid **)0) != DCI_SUCCESS) { printf("FAILED: init_handles()\n"); return DCI_SUCCESS; } return DCI_ERROR; } /* 主函数入口 */ int main() { text *DbName = (text *)"KingbaseES"; text *username = (text *)"SYSTEM"; text *password = (text *)"MANAGER"; int logged_on = FALSE; DCIDefine *dfnhp[2]; DCILobLocator *lobp[2]; text *sqlstmt = (text *)"SELECT C2,C3 FROM TAB2"; /* 初始化各种句柄 */ if (init_handles(&envhp, &errhp)) { printf("FAILED: init_handles()\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 登录到数据库服务 */ if (log_on(envhp, errhp, username, password, DbName)) { printf("FAILED: log_on()\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } logged_on = TRUE; if (DCIHandleAlloc((dvoid *)envhp, (dvoid **)&stmthp, (ub4)DCI_HTYPE_STMT, (CONST size_t)0, (dvoid **)0)) { printf("FAILED: alloc statement handle\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 表结构为：CREATE TABLE TAB2(C1 INT PRIMARY KEY, C2 CLOB, C3 BLOB) */ /* 请预先给该表插入一定数量的数据再运行本测试用例。 */ lobp[0] = (DCILobLocator *)0; lobp[1] = (DCILobLocator *)0; alloc_lob_desc(envhp, &lobp[0]); alloc_lob_desc(envhp, &lobp[1]); if (DCIStmtPrepare(stmthp, errhp, sqlstmt, (ub4)strlen((char *)sqlstmt), (ub4)DCI_NTV_SYNTAX, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtPrepare() select\n"); report_error(errhp); return DCI_ERROR; } dfnhp[0] = (DCIDefine *)0; dfnhp[1] = (DCIDefine *)0; if (DCIDefineByPos(stmthp, &dfnhp[0], errhp, (ub4)1, (dvoid *)&lobp[0], (sb4)4, (ub2)SQLT_CLOB, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &dfnhp[1], errhp, (ub4)2, (dvoid *)&lobp[1], (sb4)4, (ub2)SQLT_BLOB, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIStmtExecute(svchp, stmthp, errhp, (ub4)0, (ub4)0, (CONST DCISnapshot *)0, (DCISnapshot *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtExecute() select\n"); report_error(errhp); return DCI_ERROR; } while (1) { if (DCIStmtFetch(stmthp, errhp, 1, DCI_FETCH_NEXT, 0) != DCI_SUCCESS) break; /* 读取当前游标位置的大对像记录 */ Read_from_loc(svchp, errhp, lobp[0]); Read_from_loc(svchp, errhp, lobp[1]); } DCIDescriptorFree((dvoid *)lobp[0], (ub4)DCI_DTYPE_LOB); DCIDescriptorFree((dvoid *)lobp[1], (ub4)DCI_DTYPE_LOB); /* 登出数据库服务，并清理各种句柄 */ return finish_demo(logged_on, envhp, svchp, errhp, stmthp); }5.5. 将数据写入大字段
为了节省篇幅，本示例不再重复写出上面示例中实现的 init_handles、log_on、finish_demo和 report_error 等函数，以及包含的头文件列表，仅给出主函数的实现。
#define COMMENT(x) (void)fprintf(stdout, "\nCOMMENT: %s\n", x) #define WRITESIZE 1024 * 1024 void write_from_loc(DCISvcCtx *svchp, DCIError *errhp, DCILobLocator *lobp) { char *buf = (char *)malloc(sizeof(char) * 1024); ub4 writesize = 0; ub4 amtp; ub4 lenp = 0; sb4 err; COMMENT("Read from the locator."); memset(buf, 'a', 1024); printf("\n--------------------------------------------------------------\n"); /* 读定位器 */ do { amtp = 1024; err = DCILobWrite(svchp, errhp, lobp, &amtp, 1, (dvoid *)buf, (ub4)1024, 0, (dvoid *)0, 0, (ub2)0, (ub1)SQLCS_IMPLICIT); if (err == DCI_SUCCESS) writesize += amtp; } while (writesize < WRITESIZE); printf("\n--------------------------------------------------------------\n"); printf("\n"); free(buf); } /* 分配一个大字段存贮描述结构指针 */ sword alloc_lob_desc(DCIEnv *envhp, DCILobLocator **lobsrc) { if (DCIDescriptorAlloc(envhp, (dvoid **)lobsrc, (ub4)DCI_DTYPE_LOB, (size_t)0, (dvoid **)0) != DCI_SUCCESS) { printf("FAILED: init_handles()\n"); return DCI_SUCCESS; } return DCI_ERROR; } /* 主程序入口 */ int main() { text *DbName = (text *)"KingbaseES"; text *username = (text *)"SYSTEM"; text *password = (text *)"MANAGER"; int logged_on = FALSE; DCIDefine *dfnhp[2]; DCILobLocator *lobp[2]; text *sqlstmt = (text *)"SELECT C2, C3 FROM TAB2 WHERE C1=1 FOR UPDATE"; char sql[1024]; /* 初始化各种句柄 */ if (init_handles(&envhp, &errhp)) { printf("FAILED: init_handles()\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 登录到数据库服务 */ if (log_on(envhp, errhp, username, password, DbName)) { printf("FAILED: log_on()\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } logged_on = TRUE; if (DCIHandleAlloc((dvoid *)envhp, (dvoid **)&stmthp, (ub4)DCI_HTYPE_STMT, (CONST size_t)0, (dvoid **)0)) { printf("FAILED: alloc statement handle\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 表结构为：CREATE TABLE TAB2(C1 INT PRIMARY KEY, C2 CLOB, C3 BLOB) */ lobp[0] = (DCILobLocator *)0; lobp[1] = (DCILobLocator *)0; alloc_lob_desc(envhp, &lobp[0]); alloc_lob_desc(envhp, &lobp[1]); strcpy(sql, "INSERT INTO TAB2 VALUES(1, EMPTY_CLOB(), EMPTY_BLOB());"); /* 先给大字段插入一个NULL */ if (DCIStmtPrepare(stmthp, errhp, (unsigned char *)sql, (ub4)strlen((char *)sql), (ub4)DCI_NTV_SYNTAX, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtPrepare() select\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } if (DCIStmtExecute(svchp, stmthp, errhp, (ub4)1, (ub4)0, (CONST DCISnapshot *)0, (DCISnapshot *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtExecute() select\n"); return finish_demo(logged_on, envhp, svchp, errhp, stmthp); } /* 定位更新大字段 */ if (DCIStmtPrepare(stmthp, errhp, sqlstmt, (ub4)strlen((char *)sqlstmt), (ub4)DCI_NTV_SYNTAX, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtPrepare() select\n"); report_error(errhp); return DCI_ERROR; } dfnhp[0] = (DCIDefine *)0; dfnhp[1] = (DCIDefine *)0; if (DCIDefineByPos(stmthp, &dfnhp[0], errhp, (ub4)1, (dvoid *)&lobp[0], (sb4)4, (ub2)SQLT_CLOB, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIDefineByPos(stmthp, &dfnhp[1], errhp, (ub4)2, (dvoid *)&lobp[1], (sb4)4, (ub2)SQLT_BLOB, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIDefineByPos()\n"); report_error(errhp); return DCI_ERROR; } if (DCIStmtExecute(svchp, stmthp, errhp, (ub4)1, (ub4)0, (CONST DCISnapshot *)0, (DCISnapshot *)0, (ub4)DCI_DEFAULT)) { printf("FAILED: DCIStmtExecute() select\n"); report_error(errhp); return DCI_ERROR; } write_from_loc(svchp, errhp, lobp[0]); write_from_loc(svchp, errhp, lobp[1]); DCIDescriptorFree((dvoid *)lobp[0], (ub4)DCI_DTYPE_LOB); DCIDescriptorFree((dvoid *)lobp[1], (ub4)DCI_DTYPE_LOB); /* 登出数据库服务，并清理各种句柄 */ return finish_demo(logged_on, envhp, svchp, errhp, stmthp); }5.6. DIRPATH操作
typedef struct _ColAttr_t { ub4 data_offset; ub4 data_size; char *col_name; ub4 data_type; int *indp; } ColAttr_t; void InitColOffset(ColAttr_t *col, ub2 cols, ub4 *record_size) { ub4 offset = 0; int i; for (i = 0; i < cols; i++) { col[i].data_offset = offset; offset += col[i].data_size; } *record_size = offset; } sword SetTableInfo(const char *schema, const char *table, ColAttr_t *col, ub2 cols, ub4 rows, ub4 *nrows, ub1 input_type, DCIDirPathCtx **dpctxpp, DCIDirPathColArray **dpcapp, DCIDirPathStream **dpstrpp, DCIParam **colLstDescpp) { ub2 i, pos; DCIParam *colDesc; /* 列参数描述符 */ ub4 buf_size; ub1 dirpathinput = input_type; /* DCI_DIRPATH_INPUT_STREAM */ ub2 dtype = SQLT_CHR; char dfltdatemask_tbl[100] = "YYYY-MM-DD HH24:MI:SS"; DCIParam *colLstDesc = NULL; /* 列参数句柄 */ DCIDirPathCtx *dpctx = NULL; /* 直接路径上下文 */ DCIDirPathColArray *dpca = NULL; /* 直接路径列数组句柄 */ DCIDirPathStream *dpstr = NULL; /* 直接路径流句柄 */ *dpctxpp = NULL; *dpcapp = NULL; *dpstrpp = NULL; *colLstDescpp = NULL; DCIHandleAlloc((dvoid *)envhp, (dvoid **)&dpctx, (ub4)DCI_HTYPE_DIRPATH_CTX, (size_t)0, (dvoid **)0); *dpctxpp = dpctx; DCIAttrSet((dvoid *)dpctx, (ub4)DCI_HTYPE_DIRPATH_CTX, (dvoid *)table, (ub4)strlen((const char *)table), (ub4)DCI_ATTR_NAME, errhp); if (schema && strlen(schema) != 0) { DCIAttrSet((dvoid *)dpctx, (ub4)DCI_HTYPE_DIRPATH_CTX, (dvoid *)schema, (ub4)strlen((const char *)schema), (ub4)DCI_ATTR_SCHEMA_NAME, errhp); } /* 注意: 设置tbl默认日期掩码不会触发客户端库检查日期字符串，只有设置列日期掩码才会。 */ DCIAttrSet((dvoid *)dpctx, (ub4)DCI_HTYPE_DIRPATH_CTX, (dvoid *)dfltdatemask_tbl, (ub4)strlen((const char *)dfltdatemask_tbl), (ub4)DCI_ATTR_DATEFORMAT, errhp); /* 设置数据输入类型为text */ DCIAttrSet((dvoid *)dpctx, DCI_HTYPE_DIRPATH_CTX, (dvoid *)&dirpathinput, (ub4)0, DCI_ATTR_DIRPATH_INPUT, errhp); /* 设置加载列的数量 */ DCIAttrSet((dvoid *)dpctx, (ub4)DCI_HTYPE_DIRPATH_CTX, (dvoid *)&cols, (ub4)0, (ub4)DCI_ATTR_NUM_COLS, errhp); /* 获取列参数列表 */ DCIAttrGet((dvoid *)dpctx, DCI_HTYPE_DIRPATH_CTX, (dvoid *)&colLstDesc, (ub4 *)0, DCI_ATTR_LIST_COLUMNS, errhp); for (i = 0, pos = 1; i < cols; i++, pos++) { /* 获取列上的参数句柄 */ DCIParamGet((CONST dvoid *)colLstDesc, (ub4)DCI_DTYPE_PARAM, errhp, (dvoid **)&colDesc, pos); *colLstDescpp = colLstDesc; /* 列名 */ DCIAttrSet((dvoid *)colDesc, (ub4)DCI_DTYPE_PARAM, (dvoid *)col[i].col_name, (ub4)strlen(col[i].col_name), (ub4)DCI_ATTR_NAME, errhp); /* 列类型 */ if (dirpathinput == DCI_DIRPATH_INPUT_STREAM) { DCIAttrSet((dvoid *)colDesc, (ub4)DCI_DTYPE_PARAM, (dvoid *)&col[i].data_type, (ub4)0, (ub4)DCI_ATTR_DATA_TYPE, errhp); } else { DCIAttrSet((dvoid *)colDesc, (ub4)DCI_DTYPE_PARAM, (dvoid *)&dtype, (ub4)0, (ub4)DCI_ATTR_DATA_TYPE, errhp); } /* 最大数据大小 */ DCIAttrSet((dvoid *)colDesc, (ub4)DCI_DTYPE_PARAM, (dvoid *)&col[i].data_size, (ub4)0, (ub4)DCI_ATTR_DATA_SIZE, errhp); /* 释放列描述符的参数句柄 */ DCIDescriptorFree((dvoid *)colDesc, DCI_DTYPE_PARAM); *colLstDescpp = NULL; } buf_size = 64 * 1024; DCIAttrSet((dvoid *)dpctx, (ub4)DCI_HTYPE_DIRPATH_CTX, (dvoid *)&buf_size, (ub4)0, (ub4)DCI_ATTR_BUF_SIZE, errhp); /* 准备加载 */ DCIDirPathPrepare(dpctx, svchp, errhp); /* 分配句柄的时候用 */ DCIHandleAlloc((dvoid *)dpctx, (dvoid **)&dpca, (ub4)DCI_HTYPE_DIRPATH_COLUMN_ARRAY, (size_t)0, (dvoid **)0); *dpcapp = dpca; DCIAttrGet((CONST dvoid *)dpca, DCI_HTYPE_DIRPATH_COLUMN_ARRAY, (dvoid *)(nrows), (ub4 *)0, DCI_ATTR_NUM_ROWS, errhp); DCIHandleAlloc((dvoid *)dpctx, (dvoid **)&dpstr, (ub4)DCI_HTYPE_DIRPATH_STREAM, (size_t)0, (dvoid **)0); *dpstrpp = dpstr; return DCI_SUCCESS; } sword FreeDirPathHandle( DCIParam *colLstDesc, /* 列参数句柄 */ DCIDirPathCtx *dpctx, /* 直接路径上下文 */ DCIDirPathColArray *dpca, /* 直接路径列数组句柄 */ DCIDirPathStream *dpstr /* 直接路径流句柄 */) { if (colLstDesc != NULL) DCIDescriptorFree((dvoid *)colLstDesc, DCI_DTYPE_PARAM); if (dpca != NULL) DCIHandleFree((dvoid *)dpca, DCI_HTYPE_DIRPATH_COLUMN_ARRAY); if (dpstr != NULL) DCIHandleFree((dvoid *)dpstr, DCI_HTYPE_DIRPATH_STREAM); if (dpctx != NULL) DCIHandleFree((dvoid *)dpctx, DCI_HTYPE_DIRPATH_CTX); return DCI_SUCCESS; } sword DirPathLoadStream(const char *schema, const char *table, ColAttr_t *col, ub2 cols, ub4 rows, void *data, ub1 input_type) { sword retcode; ub4 rowoff; ub4 rowoff_all = 0; ub2 coloff; ub4 record_size = 0; ub4 nrows; ub4 times = 0; ub4 rows_temp; DCIParam *colLstDesc = NULL; /* 列参数句柄 */ DCIDirPathCtx *dpctx = NULL; /* 直接路径上下文 */ DCIDirPathColArray *dpca = NULL; /* 直接路径列数组句柄 */ DCIDirPathStream *dpstr = NULL; /* 直接路径流句柄 */ if (table == NULL || col == NULL) return DCI_ERROR; if (cols == 0) return DCI_ERROR; InitColOffset(col, cols, &record_size); if (!SetTableInfo(schema, table, col, cols, rows, &nrows, input_type, &dpctx, &dpca, &dpstr, &colLstDesc)) return DCI_ERROR; while (rows) { if (rows > nrows) { rows_temp = nrows; rows -= nrows; } else { rows_temp = rows; rows = 0; } retcode = DCIDirPathColArrayReset(dpca, errhp); if (retcode != DCI_SUCCESS) return DCI_ERROR; retcode = DCIDirPathStreamReset(dpstr, errhp); if (retcode != DCI_SUCCESS) return DCI_ERROR; for (rowoff = 0; rowoff < rows_temp; rowoff++) { for (coloff = 0; coloff < cols; coloff++) { if (col[coloff].indp && col[coloff].indp[rowoff_all] == -1) { retcode = DCIDirPathColArrayEntrySet(dpca, errhp, rowoff, coloff, (ub1 *)data + (rowoff_all * record_size) + col[coloff].data_offset,col[coloff].data_size, DCI_DIRPATH_COL_NULL); if (retcode != DCI_SUCCESS) return DCI_ERROR; } else { retcode = DCIDirPathColArrayEntrySet(dpca, errhp, rowoff, coloff, (ub1 *)data + (rowoff_all * record_size) + col[coloff].data_offset,col[coloff].data_size, DCI_DIRPATH_COL_COMPLETE); if (retcode != DCI_SUCCESS) return DCI_ERROR; } } rowoff_all++; } retcode = DCIDirPathColArrayToStream(dpca, dpctx, dpstr, errhp, rows_temp, 0); if (retcode != DCI_SUCCESS) return DCI_ERROR; retcode = DCIDirPathLoadStream(dpctx, dpstr, errhp); if (retcode != DCI_SUCCESS) return DCI_ERROR; } retcode = DCIDirPathDataSave(dpctx, errhp, (ub4)DCI_DIRPATH_DATASAVE_FINISH); if (retcode != DCI_SUCCESS) return DCI_ERROR; /* 为负载释放服务器数据结构。 */ retcode = DCIDirPathFinish(dpctx, errhp); if (retcode != DCI_SUCCESS) return DCI_ERROR; FreeDirPathHandle(colLstDesc, dpctx, dpca, dpstr); return DCI_SUCCESS; } -
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- 原文地址：https://blog.csdn.net/arthemis_14/article/details/126278865
